1. Department of Ear, Nose and Throat, Linyi City People's Hospital, Linyi, Shandong 276000, P.R. China
2. Department of Oncology, Linyi City People's Hospital, Linyi, Shandong 276000, P.R. China
3. Department of Ear, Nose and Throat, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, P.R. China
4. Department of Radiation Oncology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, P.R. China